Solenoid-operated, self-restricting inlet pump



July 2, 1957 .1. c. POMYKATA 2,797,546

SOLENOID-OPERATED, SELF-RESTRICTING INLET PUMP Filed Aug. 21, 1953 solIllH FIG.4

IN VEN TOR.

JOHN G. POMYKATA W1 T'ofa ag United States Patent @flhce 2,797,646Patented July 2, 1957 SOLENOID-OPERATED, SELF-RESTRICTING INLET PUlVlPJohn C. Pomykata, Whittier, Califi, assignor to North American Aviation,Inc.

Application August 21, 1953, Serial No. 375,617

7 Claims. (Cl. 103-53) The invention relates to pumps, and moreparticularly to a pump for corrosive fluids which contains aselfrestricting inlet choke requiring no moving parts or liquid seals.

Heretoforc, valves of the check type (i. e., designed for fluid flow inone direction only) have been required in the inlet passageways ofreciprocating piston pumps. Said check valves are conventionallydesigned with a spring operated closing element, such as a ball orflapper, which is forced open by the fluid pressure on the pump intakestroke to allow fluid to enter the pump chamber, and closed by thespring during the pump output stroke. In such a conventional system, themoving parts of the valve must be made of high-cost noncorrosivematerial when the pump is required to move corrosive fluids. The use ofconventional check valves in the inlet to reciprocatory pumps isobjectionable, since such valves are liable to incur fouling, the intakepressure and therefore fluid velocity generally being less than thatgenerated by the output stroke of the pump.

Also, reciprocatory pumps are normally constructed so that the fluidbeing pumped comes in contact with other moving parts, requiring fluidseals around said moving parts. This necessitates constructing the sealsand moving parts of high-cost, corrosive-resistant material, and evenunder such circumstances wear and deterioration occur fairly rapidly.Due to constructional limitations, the size and weight for a givendisplacement volume of such conventional pumps are such that they arenot adaptable for use in installations requiring a highdisplacement-size, weight ratio.

This invention contemplates the provision of an economically constructedminiature, light-weight fluid pump having no moving parts in contactwith the fluid until after the fluid is discharged from the pumpingchamber.

This invention also contemplates an improved selfcleaning,self-restricting inlet choke valve for a reciprocating pump, said chokehaving no moving parts.

This invention also contemplates actuating means for a reciprocatingpump, which means cooperates with the self-restricting inlet choke toaccomplish the desired results.

It is therefore an object of this invention to provide an improved pumpfor circulation of fluids in which the fluids are not in contact withmoving parts of the pump until after discharge thereof.

It is another object of this invention to provide a selfcleaning,self-restricting inlet choke having no moving parts.

It is still another object of this invention to provide an actuatingmeans for a reciprocating pump, which means improves the operation ofthe self-restricting inlet choke in said pump.

Other objects of invention will become apparent from the followingdescription taken in connection with the accompanying drawings, in whichFig. 1 is a cross-sectional view showing the interior details of a pumpas constructed in accordance with this invention;

Fig. 2 is a bottom plan view of the inlet choke shown in Fig. 1

Fig. 3 is a cross-sectional view of the inlet choke shown in Fig. 1illustrating a modification thereof; and

Fig. 4 is a semi-schematic view of the pump in elevation and theactuating circuit therefor.

In detail, referring to Fig. 1, the body 1 of the pump of this inventionis of generally cylindrical shape having coaxial bores 3, 4, openingoutwardly of the ends thereof and sharing a common bottom wall 5.Covering the open end of bore 3 and secured to body 1 as by bolts 6 is agenerally disc-shaped cap '7. Bellows 8 is secured at one end to theunderside of cap 7 and extends within bore 3. The other end of bellows 8is secured to a piston 9 which, before being actuated, rests at thebottom of bore 3 adjacent wall 5.

Piston 9 has depending therefrom and secured thereto rod 19 which isadapted to reciprocate in bushing 11 secured in central axialthroughbore 12 in wall 5. Held within bore 4 by inwardly directed flange13 at the open end of said bore is solenoid coil 14. Radial set screws19 serve to hold flange 13 to body 1. Electrical leads 15, 16 areprovided for supplying current to coil M for a purpose to be laterdescribed.

The end of rod 10 opposite piston 9 is adjustably secured as by bolt 17to ferromagnetic core 18, the upper end of which, at rest, is spaceddownwardly from wall 5. Core 18 extends through the bore of coil 14, andits lower end extends outwardly of flange 13 and has notched disc 20welded thereto. Core 18 is mounted for rotation and reciprocation inbushing 21 which is fixed in a circumferential recess in the interior offlange l3. Detent 22 extends from flange 13 into one of the notches 23in disc 20 so as to prevent rotation of disc 2%) and associated core 18.To retain core 18 in its extended position, helical spring 24 isprovided surrounding said core and reacting between flange 13 and disc20.

Cap 7 is ported so as to provide an inlet passageway 26 that may beconnected to a source of fluid (not shown) as by pipe 27. Positioned atthe point where passageway 26 communicates with the chamber 28, which isformed by the bellows 8 as walls, cap 7 as a top, and piston 9 as abottom, is self-restricting inlet choke 30. Choke 30 is in the form of atwo-step cylinder having a smaller diameter body portion 31 and a largerdiameter body portion 32. Smaller portion 31 is fitted into passageway26, and larger portion 32 extends into chamber 28. A central axial mainbore 33 opens outwardly of portion 31 and terminates within portion 32'.Angularly disposed with reference to bore 33 and within body portion 32of choke 30 are a plurality of passageways 34 of smaller diameter thanbore 33. Said passageways communicate with chamber 28 at the sides ofportion 32 and terminatae within portion 32 at their juncture with bore33. A plurality of similar passageways 35 formed in portion 32 terminateat and communicate with passageways 34 at their juncture therewith, andopen outwardly of portion 32 into chamber 28 at the end of portion 32.Passageways 35 are of the same or slightly smaller diameter thanpassageways 34.

An advantageous but not restrictive arrangement is shown in Fig. 1 inwhich passageways 34 are disposed at approximately 60 degrees, andpassageways 35 at approximately 20 degrees to the central axis of bore33. Passageways 34, 35 are shown approximately one-half the diameter ofbore 33, and Fig. 2 shows four passageways 34 and four passageways 35.

As a modification, Fig. 3 shows in cross-section a choke similar to thatshown in Fig. 1 and on which the same numerals are used in referring tosimilar elements. The valve in Fig. 3 contains additional passageways 36having the same angularity as passageways but disposed inwardly ofpassageways 35 toward passageway 33. Again, passageways 34 are shown asapproximately one-half the diameter of passageway 33 and passageways 35,36 are shown approximately one-third the diameter of passageway 33.

Cap 7 also contains outlet port 37 which communicates with chamber 28through valve port 38. At the point where valve port 38 communicateswith chamber 23, said valve port is formed with a circular hole, orvalve seat 39 which is adapted to be closed by needle valve element 40.Spring 41 serves to force valve element in contact with seat 39. At itsend remote from chamber 28, valve outlet port 37 communicates withchamber .42 which is enclosed by housing 43 secured vto cap 7 and body 1by bolts 6. Gasket 45 may serve to seal the joint between housing 43 andcap 7. Secured within housing 43 is accumulator bellows 44 which servesto reduce pulsations in the output of the pump. Housing 43 may be formedwith boss 48 for securing outlet pipe 49, that communicates with chamber42, to housing 43.

Fig. 4 shows a voltage source, such as battery 50, connected in seriesby leads 15, 16 to solenoid coil 14, the circuit also containingoperating switch 51. Connected in parallel with solenoid coil 14 is thecoil of relay 52 so arranged that when relay coil 52 is energized itwill open switches 53, 54. Switch 53 is in series with relay coil 52,and switch 54 is in series with solenoid coil 14, both switches beingheld in the open position by springs (not shown). Condenser 55 isconnected across relay coil 52.

In operation, when switch 51 is closed condenser 55 begins to charge anda magnetic field is built up in relay coil 52 and solenoid coil 14. Thefield built up in solenoid coil 14 attracts core 18 inwardly against theforce of spring 24. This causes piston 9 to compress bellows '8, therebydecreasing the size of chamber 28 and forcing fluid therein past valve40 through port 37 into chamber 42, thereby building up pressure inchamber 42. *This pressure will, of course, force fluid out outlet pipe49.

This output stroke also forces fluid through passageways 34 andpassageways 35 in inlet choke 30. Because of the intersection ofpassageways 34 and 35 a turbulent effect is created at said intersectionand, hence, a temporary stoppage of the flow of the fluid. Any fluidflowing past the intersection of passageways 34 and 35 will meet at theintersection of passageways 34 and main bore 33, creating there asecondary turbulent eifect assuring little or no flow of fluid out ofmain bore 33. The addition of passageways 36 in the modification shownin Fig. 3 provides a plurality of additional intersections, assuring thestoppage of fluid within choke 30. As a further modification, choke 30may be simplified by eliminating both passageways 35, 36, therebyrelying on the turbulent effect created at the intersection ofpassageways 34 and main bore 33. Because of the rapidity 10f the outputstroke as actuated by solenoid coil 14, ohoke 30 operates in effect as acheck valve.

As soon as solenoid coil 14 is energized, relay coil 52 is suflicientlyenergized to open switches 53, 54, thereby de-energizing solenoid coil14. However, condenser 55 now discharges through relay coil 52, therebycontinuing to energizes relay coil 52 and retain switches 53, 54 in theopen position. As long as switch 54 is open and solenoid coil 14de-energized, spring 24 forces piston 9 to expand bellows 8, therebydrawing fluid in inlet passageway 26 and through choke 343 into chamber23. The intakerstroke is then sufiiciently longer than the outputstroke, because of the continued energizing of relay coil 52 by thedischarge of condenser 55 therethrough, to

allow expanded chamber 28 to be again filled with fluid.

if it is desired to change the length of the stroke of piston 9, detent22 may be removed from notch 23, and core 18 rotated so as to provide alarger space between the inner end of core 18 and wall 5.

Although it has been found that best results are obtained when theintake stroke is longer in duration than the output stroke, suchcircumstances are not essential to the operation of choke 36. It is seenthat choke 33 is simple to construct, contains no moving parts to become fouled or worn and, due to the reversal of flow of fluidtherethrough, is self-cleaning.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample only and is not to be taken by way of limitation, the spirit andscope of this invention being limited only by the terms of the appendedclaims.

I claim:

1. A bellows-type pump comprising a flexible-wall forming a chamber forcontaining fluid, an inlet passageway and an outlet passagewaycommunicating with said chamber, a self-restricting choke in said inletpassageway and a check valve in said outlet passageway, a solenoidoperatively connected with said chamber for decreasing the capacitythereof when said solenoid is actuated, and an electrically poweredcircuit for intermittently actuating said solenoid, said circuitincluding a timing means having a source of a direct current potential,a relay having at least two normally closed contacts, one of saidcontacts being connected in series with the coil of said relay acrosssaid source, the other of said contacts being connected in series withsaid solenoid coil, and a condenser connected across said relay coilwhereby the time !of actuation of said solenoid is substantially lessthan the time during which said solenoid is not actuated.

2. A bellows-type pump comprising a partially closed bellows forming achamber for containing fluid, an inlet passageway and an outletpassageway communicating with said chamber, a self-restricting choke insaid inlet passageway and a check valve in said outlet passageway, asolenoid operatively connected with said chamber for decreasing thecapacity thereof when said solenoid is actuated, a source of power,switching means connected to intermittently energize the coil of saidsolenoid from said source of power, and timer means connected to controlsaid switching means in a manner to energize said coil for substantiallyshorter periods of time than said coil is de-ener'gized whereby fluid ispumped from said inlet passageway to said outlet passageway, adjustablespring means external of said solenoid for increasing the capacity ofsaid dhamber during the time when said solenoid is not actuated, andmeans for adjusting the core of said solenoid to change the distancelength of the stroke of said pump.

3. A pump comprising a bellows forming a chamber for containing fluid,an inlet passageway and an outlet passageway communicating with saidchamber, a selfrestricting choke in said inlet passageway and a checkvalve in said outlet passageway, s'aid self-restricting choke beingformed with intersecting passageways one end of which communicates withsaid chamber, a solenoid operatively connected with said chamber fordecreasing the capacity thereof when said solenoid is actuated, anelectrically powered circuit for intermittently actuating said solenoid,said circuit containing a first switch in series with said solenoid, arelay coil in parallel with said solenoid, a second switch in serieswith said relay coil, and a condenser in parallel with said relay coil,both of said switches being actuated by said relay coil.

4. A bellows-type pump comprising a bellows having one sealed endforming a chamber for containing fluid, an inlet passageway and anoutlet passageway communicating with said chamber, a self-restrictingchoke in said inlet passageway and a check valve in said outlet passage-Way, said self-restricting choke being formed with intersectingpassageways one end of which communicates with said chamber, a solenoidoperatively connected with said chamber for decreasing the capacitythereof when said solenoid is actuated, an electrically powered circuitfor intermittently actuating said solenoid, said circuit containing afirst switch in series with said solenoid, a relay coil in parallel withsaid solenoid, a second switch in series with said relay coil, and acondenser in parallel with said relay coil, both of said switches beingactuated by said relay coil, and the capacitance of said condenser beingof such a magnitude as to maintain said switches open for asubstantially greater period of time than said switches are closedwhereby fluid is caused to enter said chamber for a greater period thanthat during which fluid is forced from said chamber.

5. In a reciprocating pump, a self-restricting inlet choke comprising abody having a main bore, one end of which communicates with the inletside of said body and the other end of which terminates within saidbody, first passageways disposed at acute angles to said main bore andcommunicating between said other end of said main bore and one face ofthe outlet of said body, and second passageways disposed at acute anglesto said main bore and said first passageways communicating between saidfirst passageways and another face of the outlet of said body wherebystream of fluid forced into said first and said second passageways willimpinge each on the other causing turbulence and a temporary stoppage ofsaid streams.

6. In a reciprocating pump, a self-restricting inlet choke comprising abody having a main bore, one end of which communicates with the inletside of said body and the other end of which terminates within saidbody, first passageways disposed at acute angles to said main bore andcommunicating between said other end of said main bore and one face ofthe outlet of said body, and second passageways disposed at acute anglesto said main bore and said first passageways communicating between saidfirst passageways and another face of the outlet of said body wherebystreams of fluid forced into said first and said second passageways willimpinge each on the other causing turbulence and a temporary stoppage ofsaid streams, the total of the cross-sectional areas of said firstpassageways being approximately equal to the cross-sectional area ofsaid main bore and the total of the cross-sectional areas of said secondpassageways being less than the crosssectional area of said main bore.

7. In combination with a reciprocating pump for pumping fluids, aself-restricting inlet choke in an inlet line of the pump, said chokecomprising a body having a main bore extending internally from an inletsurface of said body, first passageways disposed at acute angles to saidmain bore and communicating between the internal end of said main boreand an outlet surface of said body, second passageways disposed at acuteangles to said main bore and said first passageways and communicating between said first passageways and another outlet surface of said body;and electrical regulating means controlling said pump insuring greaterfluid flow through said choke on the inlet stroke than on the outputstroke of said pump.

References Cited in the file of this patent UNITED STATES PATENTS325,459 Taylor Sept. 1, 1885 1,346,555 Reeves July 13, 1920 1,570,381Lea Jan. 19, 1926 2,216,703 Ericson Oct. 1, 1940 2,322,026 Jaeckel June15, 1943 2,590,217 Snyder Mar. 25, 1952 2,662,590 Reich Dec. 15, 1953

